Photoluminescent sensors or probes are a widely employed method of measuring analyte concentration, typically oxygen, within an enclosed space such as a package, container or living tissue. Briefly, analyte concentration within a package or container can be measured by inserting an analyte sensitive photoluminescent probe within the package, container or tissue, allowing the probe to equilibrate within the package, container or tissue, exciting the probe with radiant energy, and measuring the extent to which radiant energy emitted by the excited probe is quenched by the presence of the target analyte. Exemplary optical sensors are described in WO 92/19150 and CA 2,600.563. Such optical sensors are available from a number of suppliers, including Presens Precision Sensing, GmbH of Regensburg, Germany, Oxysense of Dallas, Tex., United States, and Luxcel Biosciences, Ltd of Cork, Ireland.
Analytical instruments used to read such photoluminescent probes are commonly programmed with a calibration mode that permits calibration of the instrument by having the instrument read probes that have been exposed to mediums having known concentrations of the target analyte (e.g., setting the instrument to calibration mode, reading a probe that has been placed within a container that is flushed with certified tank gas containing 0% analyte, and then reading a probe that has been placed within a container that is flushed with certified tank gas containing a known concentration(s) of analyte such as 100% analyte).
While effective for accurately calibrating optical sensors, this calibration method is time consuming and expensive.
Accordingly, a substantial need exists for a low cost system and method for accurately and reliably calibrating instruments used to read photoluminescent sensors or probes.